A wind measurement coherent lidar emits optical pulses into the atmosphere, and receives scattered light from aerosol. It obtains the Doppler shift resulting from movement of aerosol through heterodyne detection between the seed light and the scattered light of the transmission optical pulses, and measures the wind in the direction of the laser radiation. The lidar derives the Doppler shift from the peak frequency of the signal passing through the heterodyne detection and FFT processing, and derives the wind velocity width (degree of turbulence in a wind field) from the frequency width.
As a conventional lidar for wind measurement, an instrument described in Patent Document 1 is known, for example. The instrument utilizes foresight information on a wind field, and carries out wind velocity measurement at high accuracy at low SN ratio.